com.pubnub.internal.extension.JsonElement.kt Maven / Gradle / Ivy

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package com.pubnub.internal.extension

import com.google.gson.JsonElement
import com.pubnub.api.PubNubError
import com.pubnub.api.crypto.CryptoModule
import com.pubnub.internal.crypto.decryptString
import com.pubnub.internal.managers.MapperManager
import org.slf4j.LoggerFactory

private val log = LoggerFactory.getLogger("JsonElement")

private const val PN_OTHER = "pn_other"

internal fun JsonElement.tryDecryptMessage(
    cryptoModule: CryptoModule?,
    mapper: MapperManager,
): Pair {
    cryptoModule ?: return this to null

    val inputText =
        if (mapper.isJsonObject(this)) {
            // property pn_other is used when we want to send encrypted Push Notification, not whole JSON object is encrypted but only value of pn_other property
            if (mapper.hasField(this, PN_OTHER)) {
                // JSON with pn_other property indicates that this is encrypted Push Notification
                mapper.elementToString(this, PN_OTHER)
            } else {
                // plain JSON object indicates that this is not encrypted message
                return this to logAndReturnDecryptionError()
            }
        } else if (isJsonPrimitive && asJsonPrimitive.isString) {
            // String may represent not encrypted string or encrypted data. We will check this when decrypting.
            mapper.elementToString(this)
        } else {
            // Input represents some other Json structure, such as JsonArray
            return this to logAndReturnDecryptionError()
        }

    val outputText =
        try {
            cryptoModule.decryptString(inputText!!)
        } catch (e: Exception) {
            return this to logAndReturnDecryptionError()
        }

    var outputObject = mapper.fromJson(outputText, JsonElement::class.java)

    mapper.getField(this, PN_OTHER)?.let {
        val objectNode = mapper.getAsObject(this)
        mapper.putOnObject(objectNode, PN_OTHER, outputObject)
        outputObject = objectNode
    }

    return outputObject to null
}

private fun logAndReturnDecryptionError(): PubNubError {
    val pnError = PubNubError.CRYPTO_IS_CONFIGURED_BUT_MESSAGE_IS_NOT_ENCRYPTED
    log.warn(pnError.message)
    return pnError
}